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1.
Biota Neotrop. (Online, Ed. ingl.) ; 21(1): e20201111, 2021. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1142475

ABSTRACT

Abstract Araucaria Forest is one of the most threatened tropical forests in the world. Wild pig (Sus scrofa) are invasive pig that is expanding through these forests and seed removing that would be available to native fauna. Our aim was to evaluate the rates of seed Araucaria (Araucaria angustifolia) removal by both small, medium, and large mammals in areas with and without wild pig. We conducted a seed-removal experiment with three treatments differing in mammals' access to seeds, in areas with and without the occurrence of wild pig. Similar numbers of seeds Araucaria were removed by small, medium and large mammals, even in areas with wild pig. However, we verified that seed removal by small mammals is graduate over time, while large mammals, especially wild pig, remove in one event. So, we recommend long-term studies to investigate competition between wild pig and native biota and the effects of wild pig on seed dispersal and seed survival.


Resumo A floresta de Araucárias é uma das florestas tropicais mais ameaçadas do mundo. O javali (Sus scrofa) é um porco invasor que está se expandindo por essas florestas e removendo sementes que estariam disponíveis para a fauna nativa. Nosso objetivo foi avaliar as taxas de remoção das sementes do pinheiro brasileiro (Araucaria angustifolia) por pequenos, médios e grandes mamíferos, em áreas com e sem javali. Realizamos um experimento de remoção de sementes com três tratamentos diferentes que limitam o acesso das espécies de mamíferos às sementes do pinheiro brasileiro, em áreas com e sem a ocorrência de javalis. Números semelhantes de sementes de pinheiro brasileiro foram removidos por pequenos, médios e grandes mamíferos, mesmo em áreas com javalis. No entanto, verificamos que a remoção de sementes por pequenos mamíferos é gradativa ao longo do tempo, enquanto que grandes mamíferos, especialmente os javalis, removem as sementes em uma única visita. Portanto, recomendamos estudos de longo prazo para investigar a competição entre javalis e biota nativa e os efeitos dos javalis na dispersão e sobrevivência das sementes do pinheiro brasileiro.

2.
Biosci. j. (Online) ; 35(1): 267-276, jan./fev. 2019. tab, ilus, graf
Article in English | LILACS | ID: biblio-1048580

ABSTRACT

Forest structure studies may be carried out through the diametric distribution of individuals within a population, which is defined by characterizing the number of trees per unit area and diameter class intervals. The De Liocourt's q quotient can be used to assess the relationship between recruitment and mortality in forest communities because when a constant ratio occurs between the classes, it represents that the recruitment rate is similar to the mortality rate and the distribution can be considered as regular or balanced. This study aims to analyze the diametric structure of the arboreal component of a seasonal deciduous forest fragment located in the Peixe River Valley, Midwest of Santa Catarina State, Brazil. The sampled individuals were distributed in diameter classes with an amplitude of 5 cm, in which the center of the first class presented a value of 6.5 cm. Subsequently, the observed and estimated diametric distribution curves were constructed for the overall sampling and for species with the highest importance value (IV) and with different ecological attributes. The study area presented a deficit of trees in the overall and per species diameter classes when compared to a balanced forest. The De Liocourt's q quotient can be used to assess the diametric structure of deciduous forest fragments.


Estudos de estrutura florestal podem ser realizados através da distribuição dos diâmetros de indivíduos dentro de uma população, que é definida pela caracterização do número de árvores por unidade de área e intervalos de classe de diâmetro. O quociente Q de De Liocourt pode ser usado para avaliar a relação entre recrutamento e mortalidade nas comunidades florestais, porque quando uma relação constante ocorre entre as classes, ela representa que a taxa de recrutamento é semelhante à taxa de mortalidade e a distribuição pode ser considerada como regular ou equilibrado. Este estudo tem como objetivo analisar a estrutura diamétrica do componente arbóreo de um fragmento da floresta decidual localizado na região do vale do Rio Peixe, meio-oeste do Estado de Santa Catarina, Brasil. Os indivíduos amostrados foram distribuídos em classes de diâmetro com uma amplitude de 5 cm, no qual o centro da primeira classe apresentou um valor de 6,5 cm. Posteriormente, as curvas de distribuição dos diâmetros observadas e estimadas foram construídas para a amostragem global e para espécies com maiores valores de importância (IV) e com diferentes atributos ecológicos. A área de estudo apresentou déficit de árvores nas classes de diâmetro geral e por espécie em comparação com uma floresta equilibrada. O quociente Q de De Liocourt pode ser usado para avaliar a estrutura diametral dos fragmentos de floresta deciduais.


Subject(s)
Forests , Conservation of Natural Resources , Biodiversity , Ecology
3.
Mem. Inst. Oswaldo Cruz ; 114: e180598, 2019. tab, graf
Article in English | LILACS | ID: biblio-1040630

ABSTRACT

Anopheles bellator is a primary malaria vector in the Atlantic Forest. Partial sequences of timeless and Clock genes were used to assess the genetic differentiation of five Brazilian populations, which showed strong population structure (e.g. high F ST values and fixed differences) in all pairwise comparisons between Bahia sample and the others from Paraná, São Paulo and Rio de Janeiro states. Also, the resulting phylogenetic trees clearly grouped the sequences from Bahia in a different cluster with high bootstrap values. Among southern and southeastern populations low levels of genetic differentiation were found suggesting a general stability of the genetic structure.


Subject(s)
Animals , Genetic Variation/genetics , Mosquito Vectors/genetics , Anopheles/genetics , Phylogeny , Brazil , Forests , Sequence Analysis, DNA , Mosquito Vectors/classification , Malaria/transmission , Anopheles/classification
4.
Rev. bras. entomol ; 60(3): 248-254, July-Sept. 2016. tab, graf
Article in English | LILACS | ID: lil-792692

ABSTRACT

ABSTRACT Dynastinae is one of the most representative subfamilies of Melolonthidae (Scarabaeoidea) and has considerable ecological importance due mainly to interactions with plants of the families Araceae and Annonaceae. This relationship has led to the evolution of nocturnal activity patterns, which are influenced by environmental conditions. In the present study, abiotic factors were investigated to comprehend the influence on the flight patterns and identify the sex ratio of beetles from this subfamily. A study was conducted at Campo de Instrução Marechal Newton Cavalcanti in northeastern Brazil between December 2010 and November 2011. Thirteen species of Dynastinae were identified, most of which were from the genus Cyclocephala. Abundance and richness were greater in the dry season. Six species exhibited peak flight activity at specific periods of the night. More females than males were recorded for Cyclocephala distincta and C. paraguayensis. The present findings suggest that rainfall reduces the flight activity of these beetles and different time schedules may be related to mating behavior, foraging behavior and the avoidance of interspecific resource competition.

5.
Braz. j. microbiol ; 46(2): 551-555, Apr-Jun/2015. tab, graf
Article in English | LILACS | ID: lil-749710

ABSTRACT

Many microorganisms are able to cause diseases in amphibians, and in the past few years one of the most reported has been Batrachochytrium dendrobatidis. This fungus was first reported in Brazil in 2005; following this, other reports were made in specimens deposited in museum collections, captive and free-living frogs. The aim of this study was to compare singleplex and nested-PCR techniques to detect B. dendrobatidis in free-living and apparently healthy adult frogs from the Brazilian Atlantic Forest. The sample collection area was a protected government park, with no general entrance permitted and no management of the animals there. Swabs were taken from the skin of 107 animals without macroscopic lesions and they were maintained in ethanol p.a. Fungal DNA was extracted and identification of B. dendrobatidis was performed using singleplex and nested-PCR techniques, employing specific primers sequences. B. dendrobatidis was detected in 61/107 (57%) and 18/107 (17%) animals, respectively by nested and singleplex-PCR. Nested-PCR was statistically more sensible than the conventional for the detection of B. dendrobatidis (Chi-square = 37.1; α = 1%) and the agreement between both techniques was considered just fair (Kappa = 0.27). The high prevalence obtained confirms that these fungi occur in free-living frogs from the Brazilian Atlantic Forest with no macroscopic lesions, characterizing the state of asymptomatic carrier. We concluded that the nested-PCR technique, due to its ease of execution and reproducibility, can be recommended as one of the alternatives in epidemiological surveys to detect B. dendrobatidis in healthy free-living frog populations.


Subject(s)
Animals , Amphibians/microbiology , Carrier State/veterinary , Chytridiomycota/isolation & purification , Mycoses/veterinary , Polymerase Chain Reaction/methods , Brazil , Carrier State/microbiology , Chytridiomycota/genetics , Microbiological Techniques/methods , Molecular Diagnostic Techniques/methods , Mycoses/microbiology , Reproducibility of Results , Sensitivity and Specificity , Veterinary Medicine/methods
6.
Biosci. j. (Online) ; 30(5): 1529-1550, sept./oct. 2014. ilus, tab
Article in English | LILACS | ID: biblio-946709

ABSTRACT

Habitat destruction has caused Brazilian coastal lowland semideciduous forests to suffer severe fragmentation. In the state of Rio de Janeiro, especially in the northern region, these fragments are under severe threat of destruction, while data on their floristic diversity and community structure are still lacking. In this study, six secondary forest fragments (henceforth called sites) of coastal lowland semideciduous forests with areas ranging from 13 to 1200 ha were studied. The objective was to evaluate the structure and diversity of trees of these sites and relate them to the conservation status of this region. Five plots of 20 x 20 m were established in each site, totalling a sample area of 1.4 ha and all trees with DBH 5cm were sampled. The families with the highest species richness were Fabaceae, Sapotaceae, Myrtaceae and Meliaceae. The most abundant species were: Metrodorea nigra, Pseudopiptadenia contorta and Senefeldera verticillata. The richness, evenness and Shannon diversity values ranged from 59 to 89 species, 0.75 to 0.87 and from 2.59 to 3.79 nats.ind-1, respectively. Sites showed high floristic similarity. The tree density values varied from 1410 to 1840 ind.ha-1 and were within the levels expected for semideciduous forest; however, the basal area values (19.8 to 28.0 m2.ha-1) are those usually observed in disturbed forests. Despite being secondary forests, the sites had high species diversity with occurrence of tree species of recognized conservation value. Urgent action must be taken to manage and conserve these forests, such as: (i) forest corridors establish connecting fragments especially using zoochorous tree species, and (ii) use forest enrichment techniques using species that are absent or presently at low density as a result of intensive exploitation in the past.


A destruição de habitat levou as florestas estacionais semideciduais de tabuleiro brasileiras a sofrerem intensa fragmentação. No estado do Rio de Janeiro, especialmente na região norte, esses fragmentos estão sob grave ameaça de destruição e os dados sobre a florística, diversidade e estrutura da comunidade ainda são insuficientes. Neste estudo, seis fragmentos secundários de florestas semidecíduas costeiras de baixa altitude, com áreas variando de 13 a 1200 ha foram estudados. O objetivo do presente trabalho foi avaliar a estrutura e a diversidade arbórea nesses locais e relacionar esses dados com o estado de conservação da região. Cinco parcelas de 20 x 20 m, foram alocadas em cada local, totalizando uma área amostral de 1,4ha e todas as árvores com DAP 5cm foram amostradas. As famílias com maior riqueza de espécies nas áreas foram Fabaceae, Sapotaceae, Myrtaceae e Meliaceae. As espécies mais abundantes nas áreas foram: Metrodorea nigra, Pseudopiptadenia contorta e Senefeldera verticillata. Os valores de riqueza, diversidade de Shannon e eqüitabilidade, variaram de 59 a 89 espécies, 0,75 a 0,87 e 2,59 a 3,79 nats.ind-1, respectivamente. Foi encontrada alta similaridade florística entre as áreas. Os valores de densidade de árvores variou de 1410 a 1840 ind.ha-1, estando dentro do esperado para uma floresta estacional semidecidual, no entanto, os valores de área basal (19,8-28,0 m2.ha-1) são normalmente observados em florestas perturbadas. Apesar dos fragmentos estudados serem florestas secundárias, os mesmos apresentaram alta diversidade, com ocorrência de espécies de valor conservacionista reconhecido. Medidas urgentes devem ser tomadas para o manejo e conservação dos remanescentes de florestas de tabuleiro, tais como: (1) corredores florestais devem ser definidos conectando fragmentos, especialmente utilizando espécies de árvores zoocóricas e (2) técnicas de enriquecimento florestal, utilizando espécies que estão ausentes ou ocorrem com baixa densidade como resultado da exploração intensiva no passado.


Subject(s)
Meliaceae , Myrtaceae , Sapotaceae , Flowers , Rainforest , Fabaceae
7.
Rev. biol. trop ; 60(3): 1335-1343, Sept. 2012. graf, mapas, tab
Article in English | LILACS | ID: lil-659592

ABSTRACT

Habitat fragmentation leads to isolation and reduce habitat areas, in addition to a series of negative effects on natural populations, affecting richness, abundance and distribution of animal species. In such a text, habitat corridors serve as an alternative for connectivity in fragmented landscapes, minimizing the effects of structural isolation of different habitat areas. This study evaluated the richness, composition and abundance of small mammal communities in forest fragments and in the relevant vegetation corridors that connect these fragments, located in Southern Minas Gerais, Southeastern Brazil. Ten sites were sampled (five forest fragments and five vegetation corridors) using the capture-mark-recapture method, from April 2007-March 2008. A total sampling effort of 6 300 trapnights resulted in 656 captures of 249 individuals. Across the 10 sites sampled, 11 small mammal species were recorded. Multidimensional scaling (MDS) ordinations and ANOSIM based on the composition of small mammal communities within the corridor and fragment revealed a qualitative difference between the two environments. Regarding abundance, there was no significant difference between corridors and fragments. In comparing mean values of abundance per species in each environment, only Cerradomys subflavus showed a significant difference, being more abundant in the corridor environment. Results suggest that the presence of several small mammal species in the corridor environment, in relatively high abundances, could indicate corridors use as habitat, though they might also facilitate and/or allow the movement of individuals using different habitat patches (fragments).


La fragmentación del hábitat conduce al aislamiento y la reducción de los hábitats, además provoca una serie de efectos negativos sobre las poblaciones naturales, afectando la riqueza, abundancia y distribución de las especies de animales. Dentro de este contexto, los corredores biológicos sirven como una alternativa para la conectividad de los paisajes fragmentados, minimizando los efectos del aislamiento estructural de las áreas con diferentes hábitats. Este estudio evaluó la riqueza, la composición y la abundancia de las comunidades de mamíferos pequeños en fragmentos de bosque y en los corredores de vegetación relevantes que conectan estos fragmentos, localizados en el sur de Minas Gerais, sudeste de Brasil. Diez sitios fueron muestraeados (cinco fragamentos de bosque y cinco corredores biológicos ) usando el método de captura-marcaje-recaptura, desde abril de 2007-marzo de 2008. Un esfuerzo total de muestreo de 6 300 trampas nocturnas resultó en 656 capturas de 249 individuos. En los 10 sitios muestreados, se registraron 11 especies de mamíferos pequeños. Las ordenaciones del escalamiento Multidimensional (MDS) y el ANOSIM basados en la composición de las comunidades de mamíferos pequeños dentro de los corredores y los fragmentos revelan una diferencia cualitativa entre estos dos ambientes. En cuanto a la abundancia, no hubo una diferencia significativa entre los corredores y los fragmentos. Al comparar los valores promedio de abundancia por especie en cada ambiente, sólo Cerradomys subflavus mostró una diferencia significativa, siendo más abundante en el ambiente del corredor biológico. Los resultados sugieren que la presencia de varias especies de mamíferos pequeños en el entorno del corredor biológico, en abundancias relativamente altas, podría indicar el uso de los corredores como hábitat, aunque estos también podrían facilitar y/o permitir el movimiento de individuos que utilizan los diferentes parches de hábitat (fragmentos).


Subject(s)
Animals , Ecosystem , Mammals/classification , Trees , Brazil , Population Density , Population Dynamics
8.
Braz. j. biol ; 71(3): 569-575, Aug. 2011. mapas, tab
Article in English | LILACS | ID: lil-597164

ABSTRACT

The recently-discovered titi, Callicebus coimbrai, is endemic to the coastal Brazilian Atlantic Forest south of the São Francisco River, a region with a long tradition of deforestation. While a number of C. coimbrai populations have now been identified, little is known about basic population parameters. Considering the importance of this information for conservation planning, the population of a site in southern Sergipe (with a total area of forest of approximately 500 ha) was surveyed between April and October 2008. Standard line transect procedures were used in the four largest fragments, and additional monitoring included the use of playback broadcasts for the observation of titi groups. The presence of titis was confirmed in all the forest fragments at the site, including one of only five hectares. Two other primates - Callithrix jacchus and Cebus xanthosternos - were also recorded at the site, but were less abundant than titis. A total transect walk of 476 km provided 164 sightings of primates, the majority of which (104) were of Callicebus coimbrai. Titi groups ranged in size between two and five individuals. The most reliable estimate of overall population density, derived from the combined data set, was 12.6 individuals per km²;, although density was much higher in smaller (more disturbed) fragments. The total population of Callicebus coimbrai at the site was estimated to be at least 50 individuals, which may represent a considerable proportion of the population of the species remaining in the wild. In addition to its apparent tolerance of habitat fragmentation, densities of C. coimbrai recorded at the site compare favourably with those of other Atlantic Forest titi species.


O guigó-de-Coimbra-Filho recém descoberto, Callicebus coimbrai, é endêmico da Mata Atlântica do litoral brasileiro ao sul do rio São Francisco, uma região marcada pelo desmatamento. Enquanto um número de populações de C. coimbrai já foram identificadas, pouco se sabe sobre os parâmetros populacionais básicos. Considerando a importância dessas informações para o planejamento da conservação, foi feito um levantamento da população de um local no sul de Sergipe (com uma área total de floresta de cerca de 500 ha) entre abril e outubro de 2008. Procedimentos de transecção linear foram utilizados nos quatro maiores fragmentos e monitoramento adicional incluiu o uso da técnica de playback para a observação de grupos de guigós. A presença de guigós foi confirmada em todos os fragmentos de floresta no local, incluindo um de apenas cinco hectares. Outros dois primatas - Callithrix jacchus e Cebus xanthosternos - também foram registrados no local, mas foram menos abundantes do que o guigó-de-Coimbra-Filho. Um total de 476 km percorridos proveram 164 avistamentos de primatas, a maioria (104) de Callicebus coimbrai. O tamanho dos grupos desta espécie variou entre dois e cinco indivíduos. A estimativa mais confiável da densidade populacional geral, derivada do conjunto de dados combinados, foi de 12,6 indivíduos por km²;, embora a densidade tenha sido muito maior nos fragmentos menores (mais perturbados). A população total de Callicebus coimbrai no local foi estimada em pelo menos 50 indivíduos, que pode representar uma parte considerável da população remanescente da espécie na natureza. Além da sua aparente tolerância à fragmentação de habitat, a densidade de C. coimbrai registrada no local é comparada favoravelmente com a de outras espécies de guigós da Mata Atlântica.


Subject(s)
Animals , Ecosystem , Endangered Species , Pitheciidae/classification , Brazil , Population Density , Trees
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